1. Field of Invention
This invention relates to a navigation system that outputs guidance information along a route. Further, the intersection according to the invention also includes a junction point.
2. Description of Related Art
A guidance method according to a previous navigation system is explained with reference to FIG. 4 wherein a predetermined guidance route is shown and includes sections A, B, C and D. According to the guidance route in FIG. 4, a vehicle approaching guide intersection 1 makes a right turn at guide intersection 1, a left turn at guide intersection 2 and a right turn at guide intersection 3. A figure of the guide intersection 1 and an arrow indicating xe2x80x9cTurn rightxe2x80x9d are displayed on a display screen and the content thereof is audible with voice output as the vehicle approaches guide intersection 1. After passing through the guide intersection 1, the figure is redrawn to a figure of the guide intersection 2, which is then displayed on the screen with an arrow indicating xe2x80x9cTurn leftxe2x80x9d and the content thereof is audible with voice output. Each time the vehicle approaches a subsequent guide intersection, a figure of the previous guide intersection is redrawn and guidance is performed with display and voice output in the same manner explained above. This method is hereinafter called individual guidance that performs display/voice guidance on one guide intersection.
When approaching a guide intersection 1, for example, if a distance d1 between the guide intersection 1 and the next guide intersection 2 is relatively short (ex. 750 m), then a figure of guide intersection 1 is displayed on the screen with an arrow indicating xe2x80x9cTurn rightxe2x80x9d and voice output guidance is provided as in xe2x80x9cMake a right turn, then make a left turn N miles aheadxe2x80x9d thus providing guidance output for each of the immediately following two intersections. After passing through guide intersection 1, the figure is rewritten to display a figure of the guide intersection 2, which is provided with an arrow indicating xe2x80x9cTurn leftxe2x80x9d. The content of the display for guide intersection 2 is also audible with voice output to execute further route guidance. This method is hereinafter called individual display/successive voice guidance which displays one guide intersection and executes voice guidance on a plurality of guide intersections.
Further, when the distance d1 between guide intersections 1 and 2 is relatively short (ex. 150 m), a figure composed of both guide intersections 1 and 2 is displayed with arrows indicating xe2x80x9cTurn rightxe2x80x9d and xe2x80x9cTurn leftxe2x80x9d together with voice output guidance of xe2x80x9cMake a right turn, then make a left turn N miles aheadxe2x80x9d. This method is hereinafter called plural displays/successive voice guidance that performs a plurality of displays and voice guidance on a plurality of guide intersections.
Another guidance method according to a previous navigation system is explained with reference to FIG. 11, wherein exits or branch roads diverging from an expressway are all treated as intersections requiring guidance when the vehicle travels through the long section of an expressway or a motorway wherein roads are under the same road name. For example, in FIG. 11, a guidance route involving Roads 11, 12 and 13 is determined as approaching a guide intersection R1. A figure of the guide intersection R1 and an arrow indicating xe2x80x9cRight directionxe2x80x9d are displayed on a screen and the content thereof is audible with voice output directing one to Road 13. After passing through guide intersection R1 and as approaching guide intersection R2, the figure of the guide intersection R1 is rewritten to a figure of the guide intersection R2, and the arrow indicating xe2x80x9cthe directionxe2x80x9d is displayed again with the content thereof audible with voice output directing one further. Thus, guidance is performed by redrawing a previous figure of an intersection and performing display/voice guidance each time one approaches a new guide intersection in the same way as above.
Another previous navigation system is shown in FIG. 14, wherein rotary intersections are beltways to which a plurality of entering and departing roads are connected. Such rotary intersections are all treated as requiring guidance in the previous navigation system. FIG. 14 shows rotary intersections R10 to Rn in succession between a road 21 and a road n+1. A guidance route is provided straight on between the road 21 and the road n+1, wherein a voice phrase of xe2x80x9cIt is a rotary, take a straight direction. Then, take the second exit.xe2x80x9d is output in a section A1. Thereafter, in the same way, route guidance is performed at each rotary intersection by repeating and outputting the voice guidance of xe2x80x9cIt is a rotary, take a straight direction. Then, take the second exit.xe2x80x9d in the respective sections A2, An, An+1 and so on.
The previous related art therefore provides that when two guide intersections are in succession, route guidance is easy for a driver to understand by applying the above-stated three methods respectively in the appropriate case. Further, as shown in FIG. 4, when more than 3 guide intersection and the distance d1 between the guide intersection 1 and the guide intersection 2, and the distance d2 between the guide intersection 2 and the intersection 3 are both short, a method of the above plural display/successive voice guidance is applied. In such a case, when approaching the guide intersection 1, a figure composed of the intersections 1, 2 and 3 is displayed with arrows indicating xe2x80x9cTurn rightxe2x80x9d, xe2x80x9cTurn leftxe2x80x9d and xe2x80x9cTurn rightxe2x80x9d and a voice guidance of xe2x80x9cMake a right turn, then make a left turn N miles ahead. A branch point comes further ahead (or a branch point follows)xe2x80x9d is provided. The voice guidance specific to the guide intersection 3 in the form of xe2x80x9cA branch point comes ahead (or a branch point follows)xe2x80x9d is provided to avoid confusion by the driver who might become confused were the voice guidance output as merely xe2x80x9cTurn right, then left N miles ahead, then, make a right turn (or then, make a right turn, and make a left turn further ahead.)xe2x80x9d.
The related art further provides that when more than three guidance intersections adjacent to each other are in succession, display/voice guidance processing is performed on all the guide intersections at once. Therefore, the third guide intersection, and any following intersections, are displayed in a figure. Voice guidance is still provided in the form of, for example, xe2x80x9cA branch point comes ahead (or a branch point follows.)xe2x80x9d. Thus, it is difficult for a driver to recognize all the visual and audible route guidance provided. This raises a problem that route guidance is unclear.
The invention is made to solve the above problem by providing a navigation system in which the driver can easily recognize route guidance information when more than three guide intersections are in succession, and in which a memory medium stores the programs providing the route guidance information.
Further, whereas previous navigation systems perform route guidance each time a vehicle approaches a guide intersection even if the vehicle maintains travel on the same named road, which, in most cases, does not require route guidance as the route is evident to the driver, the invention eliminates confusion by eliminating route guidance at successive intersections along the same named road. The related art also poses the problem of driver confusion by presenting a large amount of information as guidance output when a plurality of guide intersections are in succession, as when a large number of rotary intersections are in succession in one display section, and route guidance is output with several similar voice phrases while driving, thus confusing the driver. The invention is made to solve the above problems by providing a navigation system in which the driver can drive comfortably without confusion by eliminating needless route guidance when guide intersections are in succession on roads under the same road name, along with a memory medium in which the programs are stored.
Further, when guide intersections are in succession and either of the above three related art methods are applied as respectively appropriate, a problem with route guidance involving expressway entrance and exit, driveways and the like, still occurs. This problem is explained with reference to FIG. 15, wherein route guidance is described with the condition that two normal roads relatively adjacent to each other intersect an expressway. The guidance route in this instance includes a general road Aa, the guide intersection 10 to the expressway entrance Bb, the expressway Cc, the guide intersection 20 to the expressway exit Dd, a normal road Ee, wherein the distance between the expressway entrance Bb and exit Dd, is less than a predetermined distance (e.g., 2 km). The Expressway Cc distance less than the predetermined distance is equivalent to the condition that the distance d1 between the guide intersections 1 and 2 is relatively short (e.g., less than 750 m) described in FIG. 4. According to the previous individual display/successive voice guidance methods, a figure of the guide intersection 10 is displayed showing general road Aa of FIG. 15, and voice guidance of xe2x80x9cMake a right turn at the expressway entrance. The expressway exit is ahead.xe2x80x9d is performed on the guide intersections 10 and 20. Once traveling in the Expressway Cc, the previous figure is rewritten to display instead a figure of the guide intersection 20, along with voice guidance of xe2x80x9cTake the right direction at the exit expressway. Then, make a right turn ahead.xe2x80x9d. This latter guidance is performed for directing travel in and through intersections 20 and 30. In the exit Dd, the previous figure is rewritten to a figure of the guide intersection 30, which is displayed along with voice guidance of xe2x80x9cMake a right turn.xe2x80x9d
However, in the above prior method, when the entrance Bb and the exit Dd are located adjacent to each other, route guidance on the exit Dd is output as one approaches the entrance Bb. Route guidance for the exit Dd is performed therefore despite a present vehicle position that is still on a normal road Aa that does not even come into the expressway directly. Moreover, route guidance is performed for Road E despite it never directly entering the expressway Cc either. Thus, a problem occurs that guidance is not clear for the driver to understand. This problem is similarly raised when a junction of one expressway and another expressway occurs in addition to the relationship between a normal road and an expressway.
The invention solves the above problems by providing a navigation system capable of performing more accurate route guidance information to a driver by separately providing route guidance for guidance intersections having different attributes. Thus, route guidance is well-organized and easily understood by a driver even as one passes through successive intersections. A memory medium in which the route guidance programs are stored is provided as well.
In order to solve the above problems, the navigation system provides for outputting route guidance information along a route and controls the route guidance information output on the basis of the successive relationship of intersections when more than three intersections requiring guidance are in succession.
The invention provides a navigation system for outputting route guidance information along a route and further comprises a means for obtaining the distance between each of the guide intersections requiring guidance on the route and a control means for judging a successive relationship of each intersection on the basis of the distance between the guide intersections obtained by the obtaining means, wherein the control means controls the content of route information on the basis of the judged successive relationship when more than three guide intersections are in succession.
The invention provides a navigation system wherein the control means draws a figure composed of guide intersections making the shortest distance when a plurality of guide intersections are in succession.
The invention provides a memory medium in which programs of a navigation system for outputting route guidance information along a route are stored, wherein the memory medium stores a program for controlling route guidance information to be output on the basis of each successive relationship of intersections when more than three intersections requiring guidance are in succession.
Further, the navigation system provides a navigation system for outputting route guidance information along a route wherein guidance on guide intersections is not performed when guide intersections are in succession and a vehicle travels on the same-named road.
The invention provides a navigation system for outputting route guidance information along a route further comprising a means for obtaining guide intersections requiring route guidance on the route and road names between the guide intersections and a control means for controlling route guidance on the guide intersections on the basis of the guide intersections and road names obtained by the obtaining means, wherein the control means control that guidance on the guide intersections is not performed when a plurality of guide intersections is in succession and the guide intersections are under the same road name.
The invention provides a navigation system that operates properly when the guide intersections are rotary intersections.
The invention provides a navigation system wherein information on distance and road names to the last intersection are output for the first guide intersection among the successive guide intersections according to claims 5 and 6.
The invention is a memory medium in which programs of a navigation system for outputting route guidance information along a route are stored, wherein the memory medium stores a program for controlling that route guidance on guide intersections is not performed when a vehicle travels on a same-named road and the guide intersections are in succession.
Further, the navigation system provides for outputting route guidance information along a route wherein the guide information to be output is controlled on the basis of road attributes to respective guide intersections when guide intersections requiring guidance are in succession.
The invention provides a navigation system for outputting route guidance information along a route further comprising a means for obtaining guide intersections requiring guidance on the route and road attributes to the guide intersections and a control means for outputting route guidance information on guidance intersections on the basis of the successive relationship of the guide intersections and road attributes to the guide intersections obtained by the obtaining means, wherein the control means controls route guidance information on the basis of each road attribute to the guide intersection when the guide intersections requiring guidance are in succession.
The invention provides a navigation system for outputting route guidance information along a route further comprising a means for obtaining guide intersections requiring guidance on the route and a judgment means for judging whether the guide intersections obtained by the obtaining means are respectively an entrance or an exit and a distance between the entrance and the exit, wherein the control means controls that individual route guidance is performed respectively for the entrance and the exit when the distance between the entrance and the exit is within a predetermined distance.
The invention provides a memory medium in which programs of a navigation system for outputting guide information along a route are stored, wherein the memory medium stores a program for controlling route guidance information to be output on the basis of each road attribute to the guide intersection when the guide intersections requiring guidance are in succession.
According to the invention, a driver can easily identify route guidance information since successive relationships of guide intersections are judged to control route guidance output on the basis of the judged result.
Further, a driver can have a pleasant driving experience without confusion caused by excessive route guidance information by eliminating successive route guidance information for successive guide intersections on the same-name road.
Further, more accurate route guidance information is provided to a driver by organizing route guidance according to guide intersections having different attributes at an appropriate time when the vehicle is traveling the various intersections. For example, when the vehicle enters an expressway, route guidance information thereon is output, as in, xe2x80x9cTake the right direction at the expressway entrance, which is 300 m aheadxe2x80x9d. Similarly, when the vehicle is departing from the expressway, guidance information thereon is output, as xe2x80x9cTake the right direction 700 m ahead, which is the expressway exitxe2x80x9d, for example. Thus, it is controlled that route guidance information is made by distinguishing between approaching and departing, for example, even if the entrance and exit are located adjacent to each other. Further route guidance information on each point can be identified correctly since route guidance is output by controlling that guidance on the entrance is performed at the entrance.